Dynamic Characteristic Analysis of a Rotor System with Rub-impact Fault Considering Rotor-stator Misalignment

In this paper, taking a single span flexible rotor system with two discs as the research object, the finite element model of the rotor-bearing system is established. The stator is simplified as a group of equispaced points along the circumference and the rotor as a point based on the contact dynamic theory. The rotor-stator rubbing is simulated using multiple point-point contact elements, the separation and the contact of the rotor and stator are determined by the change of the cylindrical gap, and the rotor and stator model are coupled by nonlinear contact force. By adopting the augmented Lagrangian method to deal with contact constraint conditions, Coulomb friction model to simulate rotor-stator frictional characteristics, the responses of the rotor system with rubbing are analyzed. The effects of rotating speeds and rubbing stiffness on normal rubbing forces are discussed under asymmetrical rotor-stator clearance conditions. The results show that there may be different rubbing forms (local rubbing and full rubbing) and transient impact forces under four cases with rotating speeds. Rubbing stiffness has the greatest effects on the rubbing force, the amount of misalignment affects mainly the transient impact force and does not affect the normal rubbing force at the stable rubbing stage.

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Analizowano układ wirnika z dwoma dyskami. Symulowano tarcie między wirnikiem i stojanem a separacja była uwzględniana jako zmiana cylindrycznej szczeliny.